oboe: cleanup resampler comments
diff --git a/src/common/README.md b/src/common/README.md
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+# Notes on Implementation
+
+## Latency from Resampling
+
+There are two components of the latency. The resampler itself, and a buffer that
+is used to adapt the block sizes.
+
+1) The resampler is an FIR running at the target sample rate. So its latency is the number of taps.
+From MultiChannelResampler.cpp, numTaps is
+
+ Fastest: 2
+ Low: 4
+ Medium: 8
+ High: 16
+ Best: 32
+
+For output, the device sampling rate is used, which is typically 48000.For input, the app sampling rate is used.
+
+2) The is a block size adapter collects odd sized blocks into larger blocks of the correct size.
+
+The adapter contains one burst of frames, from getFramesPerBurst(). But if the app specifies a
+particular size using setFramesPerCallback() then that size will be used.
+Here is some pseudo-code to calculate the latency.
+
+ latencyMillis = 0
+ targetRate = isOutput ? deviceRate : applicationRate
+ // Add latency from FIR
+ latencyMillis += numTaps * 1000.0 / targetRate
+ // Add latency from block size adaptation
+ adapterSize = (callbackSize > 0) ? callbackSize : burstSize
+ if (isOutput && isCallbackUsed) latencyMillis += adapterSize * 1000.0 / deviceRate
+ else if (isInput && isCallbackUsed) latencyMillis += adapterSize * 1000.0 / applicationRate
+ else if (isInput && !isCallbackUsed) latencyMillis += adapterSize * 1000.0 / deviceRate
